code: def test_forward_prefix_tuning(self):
      model = self.get_model()
      self.run_forward_test(model, PrefixTuningConfig(flat=True))
  
file_path: adapters/tests/methods/test_prefix_tuning.py
imports: import torch
  from adapters import ADAPTER_MODEL_MAPPING, AutoAdapterModel, PrefixTuningConfig
  from transformers import CLIPConfig
  from transformers.testing_utils import require_torch, torch_device
  from .base import AdapterMethodBaseTestMixin
label_desc: Use image node_id 6 for calling the PrefixTuningTestMixin obj's underlying member method code with example usage: obj.test_forward_prefix_tuning() without return types